07 AprMetal Detectors: How do they work?

It is common to find people with metal detectors trying to hunt for treasure mostly along the beaches. Ask them how the metal detectors work and they will have no answer for you. The metal detectors are also used in the security industries (see here) to ensure that people are not carrying any weapons to a secured place. The metal detectors come in all shapes and size. From the small handheld detector to a large mounted detectors. The detectors use different technologies, but they are somehow related. The application of the technology is limited to the user needs.

Components of the metal detector

Before looking into the working of the metal detector, it is important to learn about the components and their use. Here are the components for any basic metal detector.

  1. Stabilizer – the work of the stabilizer is to keep the metal detector steady while operating it in an area. This part is optional depending on the type of metal detector you are using.
  2. The control box – this is where all the magic happens. The control box has the circuits for both sending and receiving the signals. It has the necessary controls that a person needs to operate the metal detector. In addition, there is the speaker for the output and the microprocessor for the information processing. The batteries too are attached to the control box to power the circuits.
  3. Shaft – the shaft connects the control box to the search coil. The shaft is easily adjustable depending on the height of a person. You can always pick the correct height level based on the comfort level. The shaft still carries the cables for relaying the signal to and from the search coil. The signals are important to ensure the correct reading.
  4. Search coil – this is the part that is responsible for searching the metal. It is often called the search head or antenna.

The new metal detectors have a jack port where a person can connect the headphones for clear hearing of the change in signals. You can learn more about the function of metal detectors and read reviews and learn about the different types of metal detectors over at the Metal Detector Judge.


The operation of a metal detector is quite simple. Turn on the unit and move it slowly over the area to be scanned. Whenever you pass the detector over an area with a metal, there will be an audible sound to signify the presence of a metal. The key is to move slowly in the area of interest so that the detector can pick up the clear signals.

Consider a metal detector that uses the very low frequency technology. It is the most popular metal detector used today in many places. The detector has two main coils, the transmitter coil, and receiver coil. The transmitter coil is the outer coil loop that has a coil of wire. When electricity is sent along the wire, there is a current induced in the coil to create an electromagnetic field. As the magnetic field pulses in the coil move back and forth in the coil, it will interact the any metal conductive objects. The metals will in turn generate weak magnetic pulses that are picked up by the receiver coil. The receiver coil transmits the pulses to the control box for display.

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